Crank arm quick release device of bicycle

Abstract

The crank arm quick release device of a bicycle includes a fixing threaded sleeve screwed on the rotation shaft of the pedal, and a crank arm formed with locking recesses for locking and fixing the fixing threaded sleeve. Thus, the pedal may be mounted on the crank arm easily and quickly.

What is claimed is:  
     
       1. A crank arm quick release device of a bicycle, comprising: 
       a pedal, having one end formed with a rotation shaft which has a free end formed with a screw portion having an outer thread;  
       a fixing threaded sleeve, having a center formed with a screw bore screwed on the screw portion of the rotation shaft of the pedal, the fixing threaded sleeve having an outer wall protruded with two radially opposite locking flanges; and  
       a crank arm, having a free end formed with a mounting hole for insertion of the fixing threaded sleeve, the mounting hole of the crank arm being having a wall formed with two insertion guide grooves for insertion of the two locking flanges of the fixing threaded sleeve, each of the two insertion guide grooves having one side formed with a locking recess for locking the respective locking flange of the fixing threaded sleeve by rotation of the fixing threaded sleeve, the locking recess of each of the two insertion guide grooves being distributed on a diameter of the mounting hole.  
     
     
       2. The crank arm quick release device of a bicycle in accordance with  claim 1 , wherein the two locking flanges of the fixing threaded sleeve form an eccentric arrangement, and the two opposite insertion guide grooves of the mounting hole of the crank arm form an opposite eccentric arrangement. 
     
     
       3. The crank arm quick release device of a bicycle in accordance with  claim 1 , wherein the rotation shaft of the pedal is fitted with a washer which is mounted between the fixing threaded sleeve and the rotation shaft.